Development of space frame structures using pultruded GFRP components

Fiber reinforced polymer (FRP) materials are well known for their excellent properties such as high strength, light weight and corrosion resistance. Compared with other reinforcements, the use of glass fibers further reduces raw material costs and introduces environmentally friendly characteristics such as low energy consumption and low carbon dioxide emissions. Pultrusion is a continuous and highly economical manufacturing method for producing constant cross-section FRP structural profiles. All the above advantages encourage the use of pultruded glass fiber reinforced polymer (GFRP) materials for civil engineering applications. However, compared with steel, GFRP materials have lower elastic modulus, lower shear strength, and poor ductility. The low elastic modulus poses a concern for design serviceability considering the low material stiffness. The low shear strength implies that premature shear failure may prohibit full utilization of the material’s potential. The lack of material ductility may prevent the incorporation of pre-failure warnings. It seems, however, that these disadvantages can be overcome at the structural level by incorporating pultruded GFRP profiles into a space frame configuration, as a structural form with high inherent structural stiffness because of the load distribution in a three-dimensional configuration. The structural members in a space frame are subjected mainly to axial rather than shear loading. Besides, space frame structures assembled by linear elastic FRP materials can achieve large nonlinear deformation behavior at structural level through progressive buckling of the members in compression. In this PhD study, a connection system is developed to integrate the pultruded GFRP profiles into a space frame structure and the mechanical performance of the resulting space frame is explored.